Abstract: Method and device for producing elastane threads from spinning solutions using recycled elastane material.

Abstract: A device for mixing and reacting multiphase gaseous and liquid mixtures is disclosed. The device comprise in sequence a first inflow cylindrical space, at least one cylindrical chamber tapering towards said cylindrical space, a second cylindrical space positioned perpendicularly to said first cylindrical space, and an outflow space. Also disclosed is a method of using the device, in particular in the interfacial process for preparing diphenyl carbonates or polycarbonates.

Abstract: An axial conveyor is described, in particular for conveying gas/liquid dispersions, wherein the conveying elements comprise a wall-sweeping edge pointing in the direction of the pressure side of the conveying elements. The axial conveyor is particularly suitable as a circulating member in loop reactors. A process comprising conveying gas/liquid dispersions as well as a process for carrying out chemical reactions directly reacting gas with gases not completely dissolved in a liquid medium, or optionally in the presence of finely divided solids, through the use of an axial conveyor, is also disclosed.

Abstract: Continuously operated, two-part crystallizer which is particularly suitable for the resolution of racemic mixtures, and process for separating solid mixtures which are difficult to separate, in particular racemates.

Abstract: The invention relates to the continuous production of polyurethane and polyurethane urea prepolymers by reaction of polyisocyanates with isocyanate-reactive compounds in a mixing nozzle.

Abstract: Mononitrohalogenobenzenes can be prepared by mixing halogenobenzene, nitric acid, sulphuric acid and water intensively with one another, simultaneously or in succession in their total quantity, and by redispersing them at least twice in the case of continuous preparation, applying a mixing energy of 1-40 watts per liter of the overall reaction mixture, preferably 3-30 W/l, largely suppressing back-mixing in the continuous procedure, and observing adiabatic reaction conditions.

Abstract: Mononitrotoluenes can be prepared by intensively mixing together toluene, nitric acid, sulphuric acid and water, simultaneously or successively in their total amount, and, in the case of continuous preparation, redispersing the mixture at least twice, for which purpose a mixing energy of 1 to 40 watts per liter of the total reaction mixture, preferably 3 to 30 W/l, is employed per volume of the reactor, and, for the continuous procedure, the back mixing is substantially repressed. Adiabatic reaction conditions are maintained.

Abstract: Aromatic diamines and polyamines are produced by a continuous process for the catalytic hydrogenation of the corresponding dinitro and polynitro compounds at elevated temperature. Heat removed from the reaction mixture may be used to produce steam with an overpressure of .gtoreq.2 bar.

Abstract: The present invention relates to the continuous production of polyurethane and polyurethane urea elastomers by reaction of polyisocyanates with isocyanate-reactive compounds in a mixing nozzle.

Abstract: The present invention relates to a process for the continuous preparation of organic mono- or polyisocyanates by the reaction of the mono- or polyamines corresponding to the mono- or polyisocyanates with phosgene dissolved in an organic solvent. The phosgene solution and the amine component, optionally also in the form of a solution, are brought together inside a nozzle (1) by subjecting the stream of one component to a constriction (3) and supplying the other component into this constriction (3) from the side as partial streams through several apertures (5).

Abstract: This invention relates to a process for the continuous production of an organic monoisocyanate or polyisocyanate in a single stage reaction. A reaction mixture is formed by continuously mixing, at a temperature elevated above room temperature but not exceeding about 150.degree. C., a solution in a substantially inert organic solvent of a monoamine or polyamine corresponding to the monoisocyanate or polyisocyanate and a solution in a substantially inert organic solvent of phosgene. The reaction mixture is continuously passed upwards from below through a reaction column comprising at least 10 separate chambers separated by perforated plates, wherein each perforation of said perforated plates has a diameter of less than about 20 mm.

Abstract: The invention relates to a process for the halogenation of organic compounds in the liquid phase using gaseous halogenating agents, the gaseous halogenating agents being metered into the reaction vessel at such an entry velocity that a gas jet is formed in the reaction mixture at the point of entry of the halogenating agent and the formation of individual gas bubbles at the point of entry is prevented.

Abstract: A method is provided for controlling the flow of liquid through a column separated by vertically spaced plates into compartments to determine the height of liquid on a plate wherein the liquid is flowed through tubes from compartment to compartment and the rate of flow through the tubes is regulated by a throttle valve responsive to gas pressure below a plate or to the height of liquid in a compartment.

Abstract: A process for the preparation of a chloroanthraquinone or a bromoanthraquinone comprising treating a molten mixture of at least one nitroanthraquinone and diluent with halogen at a temperature of about 180 to 300.degree. C, the diluent being present in at least about 10% by weight of the mixture and comprising at least one chloroanthraquinone or bromoanthraquinone. The diluent may correspond to the halogenoanthraquinone obtained from the nitroanthraquinone by replacement of the nitro group. A portion of the product can be recycled as diluent for further reaction.